Highly saline fluids from a subducting slab as the source for fluid-rich diamonds

摘要: The infiltration of fluids into continental lithospheric mantle is a key mechanism for controlling abrupt changes in the chemical and physical properties root, as well diamond formation, yet origin composition involved are still poorly constrained. Such trapped within diamonds when they form so provide unique means directly characterizing that percolate through deep mantle. Here we show clear evolutionary trend, identifying saline parental to silicic carbonatitic melts, from Northwest Territories, Canada. Fluid-rock interaction along with situ melting cause compositional transitions, traverse mixed peridotite-eclogite lithosphere. Moreover, chemistry fluids--especially their strontium isotopic compositions--and timing host formation suggest subducting Mesozoic plate under western North America source fluids. Our results imply strong association between subduction, metasomatism fluid-rich emphasizing importance subduction-derived affecting